Fix typos in FilterExtensions.cs

[gregleon]

Prerequisites

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• I have verified that there are no overlapping pull-requests open

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• I have provided test coverage for my change (where applicable)

Description

Just a simple typo fix.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@fab07ab). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1139   +/-   ##
=========================================
  Coverage          ?   82.27%           
=========================================
  Files             ?      678           
  Lines             ?    29216           
  Branches          ?     3278           
=========================================
  Hits              ?    24038           
  Misses            ?     4483           
  Partials          ?      695           

Flag	Coverage Δ
#unittests	82.27% <ø> (?)

Impacted Files	Coverage Δ
.../Processing/Extensions/Filters/FilterExtensions.cs	100.00% <ø> (ø)
...ocessors/Transforms/Resamplers/LanczosResampler.cs	100.00% <0.00%> (ø)
...harp/Processing/Processors/Filters/HueProcessor.cs	100.00% <0.00%> (ø)
...p/Metadata/Profiles/Exif/Values/ExifSignedShort.cs	14.28% <0.00%> (ø)
...Metadata/Profiles/Exif/Values/ExifRationalArray.cs	68.00% <0.00%> (ø)
...rp/PixelFormats/Utils/Vector4Converters.Default.cs	100.00% <0.00%> (ø)
src/ImageSharp/GraphicsOptions.cs	100.00% <0.00%> (ø)
.../Metadata/Profiles/ICC/Various/IccTagTableEntry.cs	46.66% <0.00%> (ø)
src/ImageSharp/Formats/Bmp/BmpEncoder.cs	100.00% <0.00%> (ø)
...lorSpaces/Conversion/ColorSpaceConverter.CieLuv.cs	100.00% <0.00%> (ø)
... and 669 more

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[antonfirsov]

Thanks! Can you sign the CLA so we can merge?

[gregleon]

CLA signed